We are building an ICF home and the blocks have 2-5/8" on each side. Approx R-22. We have thye basement completed with Fox blocks. I think it would be a good investment to add 4" additional to the outside. It all gets covered with EFIS stucco product.

Those who have done heat load calc's, Does it make sense to add foam to an ICF block?

Patrick T

I guess that would depend on your Heat Loss/Gain. Also, if I was in a Heating dominated climate, I would add the extra foam to the inside, and on the outside for a Cooling dominated climate.

PanelCrafters,

I was hoping you'd reply. I thought I've seen in some post where you state, "super insulate and ICF is not super insulated". What would be super insulated?

We are in Southern Indiana. We are both heating and cooling. Due to drywall use on the inside, I'd prefer to add to the outside.

Thanks,

Patrick T

I consider Super Insulated to be walls at around R-40. Most ICF's are around R-20 to R-24. And, I prefer to stop the the heat from reaching the concrete core of the wall. At that point, what is the heat doing? That is somewhat unknown. It's obviously going to try and heat that concrete, but with the concrete connected to a cooler ground, it's probably just lost. I understand wanting to use the built-in webs for hanging the drywall. Maybe you can get a thicker block?

You are having, or have had, a heating and cooling load calculation done, right? Whoever is doing the calc can redo it with the added insulation and that way you'll know for sure. The greatest heat loss and gain per area of wall will be the windows. If you have a high percentage of area in windows then the additional insulation won't be as beneficial as it would be if you have a minimum amount of window area. What are you doing for roof or attic insulation? You may be better off to put your money there. That's why you need a heating/cooling calculation done.

dmaceld,

 

heat load is being done now and we have proposed adding the extra insulation. The roof is a flat concrete slab on Hambro joists. We have 16" to work with and plan to put as much as we can. As per the windows, we do have our South and South East walls with lots of glass. We hope to have nice passive solar gains during the day. I would also like to incorperate insulated shutters for the coldest days of the years.

Patrick T 

 

PatrickT,

 

Please check your messages.  I'd like to learn more about your project.  I'm in the Indianapolis area and hope to be working a project like yours.

 

Thanks,

Bruce

What have you found for insulated shutters? or interior window insulation?